Ujt as relaxation oscillator, Electrical Engineering

UJT as relaxation oscillator:

The UJT relaxation oscillator is shown in fig. it consist of a UJT and a capacitor C which is charged through a variable resistance R when VBB is switched ON. R1 and R2 are the external resistances such that R1 << R2, R1 is less than 50. The inclusion of these resistances provides spike waveforms. Here the negative resistance region of the UJT is used. The discharge of the capacitor through UJT develops a saw tooth output as shown in fig. when the circuit is switched on, the capacitor c starts charging through R. during charging period, the voltage across capacitor increases in an exponential relation till it reaches the peak point voltage VB. At this instant of time UJT switches to its slow resistances conducting mode. So, the capacitor small due to small valued of R1 so C discharges abruptly. As the capacitor voltage condenser stars charging again and the next cycle begins.

Posted Date: 2/8/2013 2:57:12 AM | Location : United States







Related Discussions:- Ujt as relaxation oscillator, Assignment Help, Ask Question on Ujt as relaxation oscillator, Get Answer, Expert's Help, Ujt as relaxation oscillator Discussions

Write discussion on Ujt as relaxation oscillator
Your posts are moderated
Related Questions
Automatic Voltage Booster The functioning of Automatic Voltage Booster (AVB) is same to in which of the series capacitor. Automatic Voltage Booster is an on-load tap changer.

Q. Consider an elementary three-phase, four-pole alternator with a wye-connected armature winding, consisting of full-pitch concentrated coils.  Each phase coil has three turns,

Optimal Filtering A system identi?cation structure is shown in Figure 1. The discrete-time signal [ ] forms the input to an unknown system represented by a moving average

a single phase is supplied with sinusoid voltage v(t)=200cos(377t).the resulting instantaneous power is p(t)=800+1000cos(754t-36.7). find

Write a note on superconductors. Superconductors- The resistivity of most metals rises with increase in temperature and vice-versa. Some metals and chemical compounds are there

What is the purpose of carry (c) flag and zero (z) flag? Carry flag conatins the carry after addition or borrow after subtraction. This carry flag also shows error conditions,

An ice plant produces 12tonn of ice per day at 0 0 C using water at 300C. The plant operates on reversed Carnot cycle between -15 0 C and 28 0 C. If the actual C.O.P. is 50% of the

DESIGN SR LATCH WITH UNIVARSAL LOGIC GATES.DRAW AND EXPLAIN THE LOGIC DIAGRAMS

Modify the design of the circuit shown in FIGURE and draw a circuit diagram to provide rotary actuation in both directions using a single direction pump (to replace the bi-directio

Framework for Indicators in Electricity Sector A framework has been developed and a set of core indicators for electricity Sector has been proposed. In the first example, mapp